1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
|
/***
This file is part of PulseAudio.
Copyright 2006 Lennart Poettering
PulseAudio is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published
by the Free Software Foundation; either version 2.1 of the License,
or (at your option) any later version.
PulseAudio is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with PulseAudio; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
USA.
***/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <errno.h>
#include <pthread.h>
#include <semaphore.h>
#include <pulse/xmalloc.h>
#include <pulsecore/macro.h>
#include "semaphore.h"
struct pa_semaphore {
sem_t sem;
};
pa_semaphore* pa_semaphore_new(unsigned value) {
pa_semaphore *s;
s = pa_xnew(pa_semaphore, 1);
pa_assert_se(sem_init(&s->sem, 0, value) == 0);
return s;
}
void pa_semaphore_free(pa_semaphore *s) {
pa_assert(s);
pa_assert_se(sem_destroy(&s->sem) == 0);
pa_xfree(s);
}
void pa_semaphore_post(pa_semaphore *s) {
pa_assert(s);
pa_assert_se(sem_post(&s->sem) == 0);
}
void pa_semaphore_wait(pa_semaphore *s) {
int ret;
pa_assert(s);
do {
ret = sem_wait(&s->sem);
} while (ret < 0 && errno == EINTR);
pa_assert(ret == 0);
}
pa_semaphore* pa_static_semaphore_get(pa_static_semaphore *s, unsigned value) {
pa_semaphore *m;
pa_assert(s);
/* First, check if already initialized and short cut */
if ((m = pa_atomic_ptr_load(&s->ptr)))
return m;
/* OK, not initialized, so let's allocate, and fill in */
m = pa_semaphore_new(value);
if ((pa_atomic_ptr_cmpxchg(&s->ptr, NULL, m)))
return m;
pa_semaphore_free(m);
/* Him, filling in failed, so someone else must have filled in
* already */
pa_assert_se(m = pa_atomic_ptr_load(&s->ptr));
return m;
}
|